The present invention relates to a multinutrient supplement. More particularly, the present invention relates to a multivitamin multimineral supplement intended to be particularly useful for those adult humans over 65 years of age in improving immune system response and reducing the frequency of infection and in particular, respiratory infection.
The proportion and absolute number of individuals above the age of 65 years has grown steadily in most countries, particularly in industrialized nations and this trend is likely to continue for at least the next 100 years. At the same time, it is recognized that the elderly are ill much more often than are younger individuals. For this reason, the elderly consume almost 40% of health care resources even though they constitute only 11% of the population today. Thus the state of their health is a matter of great concern not only to the elderly themselves, but also to physicians, sociologists and health administrators.
Although both nutrition and immunology are old disciplines, it has only been about 20 years since the first systematic studies on malnutrition and immunocompetence were conducted. It is now established that nutritional deficiencies are associated with impaired immune responses. Thus, the question no longer is whether malnutrition affects immune responses, but what aspects it affects and to what extent.
Much of the early nutritional work was done on young children in developing countries, but the results of those studies have been shown to be applicable to individuals and populations in industrialized countries and to other age groups, including the elderly. Indeed there are many similarities between young infants and the elderly. Both have less than optimum immune responses, both are at high risk of developing infection, and in both, dietary factors may be important.
The main theories of ageing can be grouped into two broad types. One states that ageing is an orderly, genetically programmed event, which is the consequence of differentiation, growth and maturation. The other attributes ageing to a progressive accumulation of faulty molecules resulting in cell dysfunction and death; this may be a stochastic event resulting from random synthetic errors or a progressive damage to molecules due to their inherent instability or to environmental influences. If, for a moment, we discard the preprogrammed event theory, we have to entertain the possibility that ageing is associated with a progressive accumulation of faulty molecules and cells, which then results in a decline of physiological function, vulnerability to disease, illness, and death. Such a process can be hastened by adverse environmental factors such as nutritional deficiencies.
Ageing is generally associated with impaired immune responses. The pattern of illness observed in the elderly suggests that immune responses decline in old age. Indeed this has been shown both in man and laboratory animals. This may partly explain the frequent occurrence of infections in old age. Because of the close contact of the immune system with other systems in the body, any changes in immunocompetence may be expected to influence other organ functions as well. As immunological vigour declines, the incidence of infections, cancer, immune complex disease, autoimmune disorders, and amyloidosis increases. Infection, particularly, respiratory infection, is a major cause of illness and the fourth most frequent cause of death among the elderly. However, at least 25% of old individuals have vigorous immune responses at levels observed in young adults. Cellular and molecular manipulation to prevent or slow the decline of immune functions may be expected to delay the onset or decrease the severity of pathology associated with ageing.
It is now well established that nutrition is a critical determinant of immunocompetence. Protein-energy malnutrition and deficiencies of various nutrients impair several immune responses, particularly cell-mediated immunity. Considerable data indicate that nutritional problems are common in old age. Furthermore, the simultaneous assessment of nutritional status, immune responses and subsequent correlation analysis have suggested that impaired immunity in the elderly may be due in part to the associated nutritional deficiencies. There are limited observations to suggest that supplementation with selected nutrients may improve certain aspects of the immune system.
The well-documented effects of various nutrients in the maintenance of optimum immunity has led to limited studies of supplementation with a single nutrient or a group of nutrients. The administration of moderate amounts of zinc to subjects over 70 years of age was associated with improved delayed cutaneous hypersensitivity. In another study, such a supplement increased the number of circulating T cells, delayed cutaneous hypersensitivity and serum IgG antibody response to tetanus toxoid. The addition of zinc in vitro corrected impaired natural killer cell activity. Vitamin C supplement enhanced lymphocyte proliferation in vitro and skin reactivity to tuberculin in vivo. However, the use of megadoses of any nutrient is unwise. Large doses of zinc impair cell-mediated immune responses and neutrophil function and similar adverse effects have been shown for large doses of selenium, vitamin E and vitamin A.
The studies done to date on this subject, however, have suffered from a number of problems including use of an insufficient number of subjects, employed large pharmacologic doses of single or only a few nutrients and the duration of supplementation and follow up was limited. It has also been shown that the use of a single nutrient in large doses may create secondary alterations in requirements and malabsorption of other nutrients, and in some instances, impair immune responses or be potentially toxic. Similar effects have been shown for certain combinations of nutrients particularly those combinations concerning large amounts of iron. In one report, dietary intakes of vitamins E and D negatively systematically.
Known nutritional supplements fall into these basic categories; (1) single nutrient supplements;(2) multinutrient supplements; and (3) multinutrient supplements that are designed for individuals over 50 years of age. The problems associated with single nutrient supplements are first that they, by their definitions, contain only a single nutrient and as discussed above, large doses may have the negative effect of incurring secondary effects or of being potentially toxic. Standard multinutrient supplements such as, for example those sold under the trademarks Nature's Bounty 1, Vita Lea and Centrum as set forth in U.S. Pat. No. 4,629,625 to Gaull, generally have megadoses of component nutrients, lack certain nutrients altogether or have dosages of nutrients based upon the U.S. RDA which establishes guidelines and dietary recommendations for an age group that is completely different than the elderly. Those multinutrient supplements that have targeted individuals over 50 years of age, such as those sold under the trademarks Geritol Extend and Centrum Silver have either lacked some important nutrients, contain unduly high doses of preformed vitamin A which could prove detrimental and/or contain levels of beta-carotene and doses of preformed vitamin A which could prove detrimental and/or contain levels of beta-carotene and vitamin E that are too low.
It is apparent from the foregoing, given the known correlation between proper nutrition and immune responses particularly in the case of elderly persons with impaired immune responses, that the need exists for a multinutrient dietary supplement specifically formulated for the needs of older persons that is effective in improving their immune responses and reducing their frequency of infection, in particular respiratory infection.